Mo.sub.5 Si.sub.3 is an intermetallic compound having high hardness, high melting point, and good high temperature creep resistance. The creep resistance of Mo.sub.5 Si.sub.3 has been shown to be better than that of MoSi.sub.2 which is material commonly used in high temperature non-load bearing service applications as a result of its excellent oxidation resistance. However, MoSi.sub.2 has found limited use in load bearing applications as a result of its high creep rate at elevated temperatures, such as greater than about 1000 degrees C.
Although the Mo.sub.5 Si.sub.3 intermetallic compound exhibits good high temperature creep resistance, it unfortuantely exhibits relatively poor high temperature oxidative stability. For example, above about 1000 degrees C., the Mo.sub.5 Si.sub.3 compound exhibits catastrophic oxidation and loss of structural integrity. The inadequate high temperature oxidative stability or resistance of the Mo.sub.5 Si.sub.3 compound has limited its use in high temperature service applications. Moreover, at about 800 degrees C., Mo.sub.5 Si.sub.3 exhibits a sudden drop in mass due to oxide scale spallation, and the oxidation rate is accelerated relative to 900-1000 degrees C.
It is an object of the present invention to provide a molybdenum silicide material and products thereof having substantially improved oxidative stability at elevated temperatures, such as exceeding about 1000 degrees C., while maintaining the good high temperature creep resistance associated with Mo.sub.5 Si.sub.3 material.